Treatment of hydrocarbon oils



Patented Feb. 20, 1934 PATENT QFFICE TREATMENT OF HYDROCARBON OILSJacque C. Morrell and Gustav Egloff, Chicago,

Ill., assignors to Universal Oil Products Company, Chicago, 111., acorporation of South Dakota No Drawing. Application February 16, 1931Serial No. 516,284

4 Claims.

This invention relates to the treatment of hydrocarbon oils, and refersmore particularly to the refining of relatively low boiling hydrocarbondistillates at elevated temperatures, especially those resulting fromthe conversion of relatively high boiling hydrocarbons at elevatedtemperatures.

More specifically, the invention comprises subjecting hydrocarbon oilvapors to treatment with m mixtures of sulfur dioxide, oxygen-containinggases and steam in the presence of solid salts of metals such as, forexample, the salts of aluminum, zinc, tin, copper, lead, iron. mercury,cobalt, nickel, chromium, manganese, molybdenum, vanadium, tungsten,cadmium. and others, individual salts being used alone or mixed withothers in various combinations which have been found suitable forproducing particular treating effects. As examples of salts of metalswhich may be used may be mentioned sulfites, sulfates, acetate nitrates,chlorides, bromides, iodides, phosphates, hypochlorites. chlorates.perchlorates, permanganates, chromates, dichromates, et cetera. Asexamples of oxygen-containing gases, air, oxygen, or ozone, alone or incombination, may be mentioned ozonized air having been found to beparticularly efiicacious in some instances.

In some cases it may be found preferable to space the finely dividedsalts by supporting them on or mixing them with relatively inertmaterials of a non-metallic nature such as fullers earth, clays,bentom'te, beauxite, crushed firebrick, pumice stone, et cetera, thisexpedient serving to expose more surface and prevent the agglomerationof the salts into masses too large for effective action. The function ofthe salts or mixtures thereof employed may be of a true chemical natureor they may function merely as catalysts.

The usual method of refining cracked distillates is to subject them totreatment with sulfuric acid and alkaline solutions including plumbitesolutions consisting of litharge dissolved in alkaline solutions invarious combinations of treatment and subsequently to subject the acidtreated product to redistillation usually in the presence of steam. Thepresent invention permits the direct treatment of the hydrocarbon vaporsfrom the cracking process, reducing the cost of reagents and eliminatingthe redistillation or re-running operation, although it is within thescope of the invention to revaporize the product in a subsequentoperation and subject the vapors to treatment as described.

The invention is more particularly directed to the treatment of vaporsof lower boiling cracked hydrocarbon vapors and the treating gases em,-

ployed with the solid contacting or polymerizing materials; for example,a. suitable tower or chamber packed with a selected mixture of contactmaterials may be employed following the 5 fractionator of a crackingsystem, the gaseous reagents being introduced at a suitable point orpoints along the line of flow of the ascending or descending vapors,thus permitting contact with the solid materials of the mixture ofhydrocar- 7 bon oil vapors and the gaseous treating mixtures. Similarlyany device which permits the efficient contacting of the hydrocarbonvapors undergoing treatment with the gases and solids may be employed.The solid contacting materials may 75 sometimes be employed insuccessive strata of varying composition, or may be supported onsuperimposed plates designed to produce inti-. mate contact.

It has been found desirable to neutralize the 0, vapors before or aftercondensation and to this end the vapors may be treated with ammonia gasor pass counterflow to solutions of alkalis in auxiliary neutralizingequipment, or the condensed vapors may be treated with liquid alkalissuch as 35: solutions of caustic soda, ammonia or the like, the tracesof reagents and reaction products remaining being washed out with waterwhen found necessary.

The reactions involved in treatments conduct- 90. ed within the scope ofthe invention have been observed to produce effects comparable withthose produced by sulfuric acid of varying strength used after thecustomary methods of treatment. The amounts of reagent used will varywith the character of the vapors treated from a fraction of a percent toas high as 10% by weight of the oil vapors treated in cases whererelatively heavy treatments are desired. The proportions of sulfurdioxide, oxidizing gas and steam may also be varied to produce a widevariety of treating effects.

The effects produced upon oil vapors, particularly those produced fromthe cracking of heavy hydrocarbon oils by the use of gases and solidcontact substances characteristic of the invention are in general thoseof polymerization or condensation of relatively highly unsaturatedhydrocarbons or their derivatives, particularly 1 their sulfurderivatives. The net result is the controllable elimination of groups ofcompounds which are readily polymerized under oxidizing conditions toform substances or" a gummy or 5 resinous nature which are undesirablein motor fuel.

Various temperatures of treatment may be employed, for example, from250-500 F., more or less, and the pressures may be subatmospheric,atmospheric or superatmospherio. 'While the results may vary with theconditions employed, the pressures and temperatures are chosen so thatthe hydrocarbons are treated substantially in the vapor phase.

As specific examples of the operation of the process of the inventionand of the results obtained, a California cracked distillate ofapproximately motor fuel boiling range may be vaporized and subjected totreatment with a mixture of sulfur dioxide, oxygen and steam during thepassage of the vapors in a downward direction through a stationarycontact mass consisting of a mixture of a finely divided zinc sulfatesupported on fullers earth, the weight of the '1 earth beingapproximately four times that of the salt. The sulfur dioxide may beused in an amount equivalent to approximately four pounds per barrelwith oxygen slightly in excess of that necessary for its completeoxidation to sulfur goidioxide. Steam is used at the rate ofapproximately two pounds per barrel. The untreated product may show agum content of approximately 500 mgs. per 100 ccs. and have a reddishbrown color, with a sulfur content of approxi- -ijmately 0.35%. Thetreated product after suitable separation from spent reagents,neutralizing with alkalis and washing with water, may show a gum contentof approximately 30 regs. and a color of +25 on the Saybolt scale. Thesulfur 4c content may be found to be as low as 0.1%.

In the case of a mixed Mid-Continent and West Texas cracked distillatetreated with approximately the same amounts of reagents, the gum contentmay be reduced from 300 rngs. to

45125 and the color raised from a light amber to approximately 30 on theSaybolt scale. The sul- 1,947 sec of hydrocarbon oil vapors which has awide applicability and is capable of great variations in the methods ofoperation and the amounts of reagents employed. Therefore, the specificcases cited are not to be construed in a limiting sense upon the broadscope of the invention as many other modifications can .be used andexamples of results therefrom given.

We claim as our invention:

1. A step in the process of refining the overhead produets ofhydrocarbon oil cracking, which comprises subjecting said products inheated vaporous condition to the action of a mixture of sulphur dioxideand steam in the presence of discrete particles of a solid metallicsalt.

2. A step in the process of refining the overhead products ofhydrocarbon oil cracking, which comprises subjecting said products inheated vaporous condition to the action of a mixture of sulphur dioxide,free oxygen and steam in the presence of discrete particles of ametallic salt.

3. A process for refining hydrocarbon vapors which comprises passing thesame with sulphur dioxide and steam through an earthy contact materialcontaining discrete particles of a metallic salt.

l. A process for refining hydrocarbon vapors which comprises treatingthe same with sulphur dioxide in th presence of zinc sulphate.

JACQUE o. MORRELL. GUSTAV EGLOFF.

